Hello all builders,
I would like to place a warning here. I have received a feedback from a builder who had a problem to setup a preamp. The problem was that there is a manufacturer who produces BC560 transistors with reversed pins compared to usual and recommended type in the BOM. I am attaching images of both correct and 'wrong' (reversed) packages. Please do not use CDIL transistors. Use ON Semiconductor or Fairchild, e.g.
I would like to place a warning here. I have received a feedback from a builder who had a problem to setup a preamp. The problem was that there is a manufacturer who produces BC560 transistors with reversed pins compared to usual and recommended type in the BOM. I am attaching images of both correct and 'wrong' (reversed) packages. Please do not use CDIL transistors. Use ON Semiconductor or Fairchild, e.g.
Attachments
Dispre 2 Jfet complete...
Dear all,
I have finally completed the Dispre 2 preamplifier wiring and installed the boards in the Modushop 1U enclosure.
Initially, I was supposed to use 34AWG Belden RG-59 coax cable but due to such a short signal path, they were terribly inflexible. I stripped the shield and used the inner conductors as wiring. Input wire is about 3 inches long, while outputs are an inch or so.
The switch is just a dummy as I plan not to use one since the preamp will be on forever. Plastic extension shaft couples the ALPS pot to the knob. Green LED this time.
Fantastic huge sound when I pair it with Rod Eliiot's P3A amp.I have yet to find a pre that can better this Dispre.
Dear all,
I have finally completed the Dispre 2 preamplifier wiring and installed the boards in the Modushop 1U enclosure.
Initially, I was supposed to use 34AWG Belden RG-59 coax cable but due to such a short signal path, they were terribly inflexible. I stripped the shield and used the inner conductors as wiring. Input wire is about 3 inches long, while outputs are an inch or so.
The switch is just a dummy as I plan not to use one since the preamp will be on forever. Plastic extension shaft couples the ALPS pot to the knob. Green LED this time.
Fantastic huge sound when I pair it with Rod Eliiot's P3A amp.I have yet to find a pre that can better this Dispre.
Attachments
Nice to hear it is working well for you. In case you speak about Dispre 2 BJT board, direct replacement of BJT's with JFET's is not possible. But, it might be possible, with some changes, to use the old BJT version PCB and to implement this circuit to it.
Attachments
Carl, I remember you were one of my first customers, years ago . It is of course not impossible to start production of PCB’s of this preamp, I have all the production files. Frankly, I myself was surprised what I have measured now with better equipment, and I have also updated my web page.
Set of new measurements published here:
https://www.audiosciencereview.com/...2010-with-1-5w-32ohm-output-capability.40415/
https://www.audiosciencereview.com/...2010-with-1-5w-32ohm-output-capability.40415/
Hello Mr. Pavel Macura,Set of new measurements published here:
https://www.audiosciencereview.com/...2010-with-1-5w-32ohm-output-capability.40415/
I cannot find the schematic anymore for your MOSFET power follower, the version that also uses a MOSFET instead of the TIP141..I cannot even find the MOSFET power follower on your website
Can you please tell me where to find the schematic or send it to me? Many thanks
Thank you for your answer
Last edited:
- Home
- Source & Line
- Analog Line Level
- Preamplifier Dispre 2 - JFET